KK300 Ejector problems?

[WaltherWill]

Alright, I have the Walther KK300 aluminum and i've loved it so far. The only problem i've started having recently is the ejector starts to fail. I don't know why and I do not see any pattern (first shot in barrel, after getting warmed-up, nothing like that) but I do know that it seems to vary with the ammunition. SK Standard (I expected to use it as my practice ammo)seems to jam each and every shot but Lapua Master (match ammo) only jams about 1 in 100 rounds fired.
I've made sure to clean the ejector out quite often but it doesn't seem to have any effect.
Just wondering if anyone has had this problem or knows how to fix my dilemma.
Thanks in advance
Will

[EdR]

I shoot a kk200 and have been told by others that the wax lube they put on their bullets has potential to jam your extractor. Here is a link that has how to take a kk200 bolt apart might be helpful : http://www.pilkguns.com/tenp/spwkk200s.htm
try cleaning the ejection ports in the barrel to.

[Guest]

A dentist's pick, avaialable from a chemists, is ideal for gunky extractor slots. For day-to-day cleaning I've found an oiled cotton bud to work well.

Keeping the chamber clean may also help, some cases may just be a little tighter in there.

[Greg]

My shooter has the same problem. We do not only need to test ammo for grouping but also if extractor accepts a shell... In his rifle an edge close to a shell was too wide and therefore some ammo do not accept this. Need some mechanical work to fix the problem. I have simply used any mechancal tools to make it sharper. But still sometimes...

[WaltherWill]

well, my dad and i have done some experimenting and measuring and we believe we have determined a difference in the ammo that may be causing the problem. The width of the rim of the shell seems to determine whether or not it ejects. Using a caliper, we find that the Lapua Master's rim is consistently about .270" and ejects almost all the time. The SK ammo's rim ranges from about .274-.271. The SK rims below .272 seem to eject consistently but those wider than that do not.
Can anyone suggest reasons that a wider rim would not eject?

[WRC]

Do you mean by "jam", that the brass is stuck in the chamber?
Too wide and the extractors cannot completely clamp around it and hold on tight enough. So the force of the brass sticking in the chamber is stronger than the extractors, and they just pull past the rim instead of pulling the rim.
Or did you mean that the brass is stuck in the bolt face, and doesn't pop off?

[brvirell]

I also have the KK300, and have noticed the same problem. I didn't start noticing it until about 2000 rounds had been through it. I cleaned the extractor, dental pick, and socked it in solvent and brushed it out, after firing for about 100 rds it started up again. I was using only one brand of ammo the whole time, so I guess the only thing I can contribute is that the problem didn't start from the get go.
Has anyone contacted walther about this problem.
Also my friend whos a gun smith said "yeup thats why I told ya to buy as many extra parts for that contraption as you can while they are available."

[WaltherWill]

we think that the probelm may be that the trough that the bullet rides in before enterng the chamber is too shallow, that the bullet is going into the chamber at a slight downward angle. The shell is jamming in the chamber, not the extractors and with the bolt out, you can push a shell down into the extractors, but it comes out very easily if you push upwards on the shell. Its harder to pull it straight out, but if you push up, it practically comes out on its own.

[brvirell]

I never put the bullet into the trough, I always put it directly into the chamber, so thats not it. But you are right about the shell coming out easily if you just set it in the extractors with the bolt out, but on mine it comes out easily if you try to pull it straight out as well. As a mechanical engineer I think the extractor is a flowed design, though I still haven't figured out what exactly the problem is.

[WaltherWill]

well, I put the bullet into the chamber as well, but at least for my action, I cant actually push the bullet in until it seats completely. When the shell doesn't eject, the rim is sealed up to the vertical part of the chamber, i have to actually use a knife to get in behind the rim and extract it. And I just cant get enough pressure behind my the shell to get the bullet sealed in completely, i have to use the bolt handle for at least the last 2mm or so (usually just the downward stroke on the bolt is actually pushing the bullet). One last interesting point, if I extract an unifred bullet from the chamber after closing the bolt, the lead is actually scarred from the rifling, the bullet must be meeting the rifling before it is even fired (expaining why I cant actually completely seat the bullet myself?)

[Raymac]

I sold and serviced Walthers for more than ten years and here is what I think your problem is.....I have encountered this problem a number of times, always with a rifle that was not properly cleaned after each time it was used. There becomes a hard carbon build-up in the chamber which does not allow the bullet to seat as easily as it should. the build-up on the walls of the chamber will also grip the spent casing making extraction very difficult. In this case the extractor simply slips over the rim. Powder residue when fresh is quite soft and will come out with the minimum of cleaning provided only that the cleaning is done immediately. Carbon residue is also hydroscopic, that is to say that it absorbs water and like cement, it hardens into a layer of rock hard stuff. This hard carbonate is very hard to get out and it is at its worst at the forward end of the chamber where the rifling starts. If the firearm is not cleaned properly it will continue to build up until feed and extraction problems start. I suggest that you soak the chamber for a few days with a good nitro-solvent then scrub the hell out of it with a bronze brush. Walther extractors are a very good design and rarely cause extraction difficulties.....they should work as well as they did when the rifle was new provided the chamber is kept clean.

good luck, Ray.

[brvirell]

I'll Give That a Try.